Reorientational dynamics of glycerol derived from temperature-dependent multi-nuclear magnetic resonance relaxation data

Longitudinal H-1, H-2 and C-13 relaxation rates of [H-1(8)]glycerol and [H-2(8)]glycerol have been recorded at 250.13 MHz, 38.27 MHz and 62.89 MHz respectively, over the temperature range 260 to 350 K. In addition, the nuclear Overhauser enhancement factors of C-13 nuclei were recorded, since they depend only on the reorientational dynamics. It proved possible to fit all experimental data to a Cole-Davidson model extended by the Vogel-Fulcher-Tammann temperature dependence and the Lipari-Szabo libration parameter. Separate parameters were obtained for the inner CH and the outer CH2 groups. The overall picture of glycerol is one of a hydrogen-bonded liquid, where the outer CH2 groups perform fast librational motions whereas the inner CH group is rigidly fixed. Copyright (C) 2003 John Wiley Sons, Ltd.